It's demonstrable because in the experiments that have actually taken place, the path of the idlers is farther than the path of the signal photons. Even though it is in nanoseconds in the future, the signal photons land and produce data before the idler photons either help us detect or erase the which path data. You can extend the idler photon splitters as far off as you wish, it is proven that the results will always be the same.

to be honest the music really makes this. If you put some queer fad song like wonderful time or break my god damn stride it wouldn't have been nearly as good. Please PM me your whole playlist ASAP lol.

Seriously this sh*t really is not for this website. I mean the f*cking site was started with a picture of sean connory pointing at a video camera, not quantum physics... why does everyone take YTMND so seriously sometimes? sheesh
PS No HORSEDICK or NEDM makes this an insta fail classic

I like the "we can't outsmart them" part. It's not that we're trying to trick them, it's that we're trying to understand the fundamental laws governing quantam physics. Again, the "whether or not we observed" is a cognitive claim... which makes it seem like if the path was measured but we didn't look at it we would get an interference pattern but when we look back and see which path it took it magically changes to a non-interference pattern.

Unfortunately the "ooh, ahh" factor is just that, as I take it nobody understands the cause for these discrepancies between measured/non-measured paths? Like, "Why do the seasons change when the sun is just revolving around us once per day? Is the earth rotating on an axis once every 365 days?" A change of perspective is needed... and I don't think part 5 is going to give us any answers =(

The measurement if you include the act of us knowing the results dictates the final result, however a measurement, without us knowing, will yield an interference pattern. This is proven with the Delayed Choice Experiment.
Simply the observer KNOWING affects the outcome. There's no 2 ways about it.

I have a question (that will have to be broken into multiple parts) I was wondering if you could answer, as this is really starting to get creepy in a "wow, that's really amazing" sort of way. Suppose you had a detector, but you rigged it such that it wouldn't tell you whether or not it detected anything until you prompted it for this result, and such that you could delete the recorded result, making it impossible to ever know what the detector saw.

Basically, the situation is that the information is stored, but the human has no idea what it is, and could conceiveably never know. Here's the question: would this produce an interference pattern or a non-interference pattern? Alternatively, if the detector recorded the info but could NEVER release it to the human (it always deletes it, say, a minute after recording, and produces no output), what would show here? I suppose the basis of my question is that I'm wondering if the non-interference pattern is

Well. Theoretically, it can never be tested outright. Because if we never know, there is no way to know the results. However, this Delayed Choice Experiment, that produces potential to know the result, after the main detector has recorded an interference or noninterference pattern, shows that only if we completely erase the evidence of the path, does it produce a wave pattern. Another way to describe it would be to say, we don't really change the results by knowing, we simply understand the past better.

When we didn't know why the earth spun, did we think the earth had outsmarted us? Not understanding doesn't mean things are "clever" or "smarter" than us. Your YTMNDs fail to make your points apparent. +1 just cause you're only doing it for music.

I'm not sure why you say that it can't be tested outright. Basically, my question is just this: if you can possibly know at a later time where the particle went, but if it's also possible for you to never know, which pattern would you see? Would the particle "know" in a sense whether or not you'd see the results in the future?

I understand that humanizing the particles is not scientific, but this is science for the masses. If you understand Quantum Mechanics, WTF are u watching these in the first place?
Gabu, the only time it has produced an interference pattern when they still had the potential to know is when they found out the evidence was erased. But this happens in nanoseconds. We haven't the technology to actually place detectors light years away.

So, if I understand you, the pattern actually changes not based on the apparatus that is set up but based on the actual cognition? To restate: The pattern actually changes from an interference pattern to a non-interference pattern after looking at a printout of the results? I see an interference pattern, I look at the results, I look back, no interference...? If this is your contention... it seems ludicrous. And if it isn't then your post is extremely misleading.

I say ludicrous because that means that the physical position on the detector have moved merely because you read a piece of paper. Also, it would imply that a person who has not read the results could look at the detector and see something completely different that another person who has just read the results. It's ludicrous.

I'm not sure if I'm being clear enough regarding what I'm talking about, for which I apologize. I'm not talking about the detectors in part four, 5 light years away - obviously, this isn't going to happen. I'm just talking about a theoretical detector not found in these slides, much like the ones found in part 2, with the added features that it doesn't tell you what it saw until you ask for it and that you can erase what it saw without looking at it, and am simply curious what you'd see with it in use.

What has to be understood is that the electron or photon is never moving in two places at once, rather the sum of all paths creates a number of possible paths the given electron or photon can take. This reason, above all, makes the behavior seem spooky. Moreover, the lack of a timeliness in the interactions only proves that the given sum of all paths forms ahead of the given electron or photon.

Thus, proving there is no magical splitting particle. What this concludes is that observation has some 'sub-quantum' interaction that alters the sum of all paths, e.g. a non-local 'membrane' interaction [if you accept M-Theory]. Which means, quantum mechanics has also hit a threshold for its possible calculations of quantum entities since it has no means to 'normalize' the conception of sub-quantum interactions and/or entities.
-- Bridget Armozel

I just find it stupid (I give you props for the effort). You humanize the photons so when those of us who actually understand relativity (and other empirically proven theories) try to open our minds, we are bombarded by incomprehensible notions of photons "knowing" we are watching. It makes you sound like a new age nut trying to push that photons make up our souls (a la What the Bleep do we know). Please, if you want us to take you seriously, make a part 5 for the science-initiated.

"Ugh. Let me simplify. If we can possibly know the path it took, it goesone definite path, and acts like matter. If we don't know and can never know the direction it acts like a wave." - Ah, okay, thanks; that's basically exactly what I wanted to know.

Ah yes. I love this series. Do you plan on discussing the existance of the particle in all possible positions at once (thus explaining the interference pattern) or are you just going to leave their minds relatively intact? *laughs*

too bad that by subjecting single binary-value (detect/nodetect) photons to 50/50 probability splitters, you are actually erasing any information you could have transmitted instanteneously across 5ly by tweaking the detectors 5ly away.
nice try though.

Alright f*cker. You can't get away that easy! I still want to know just wtf is going on with these mother-f*ckin' protons! OMG! How do they KNOW!?!!?!?!?!!11Eleventy!! Do people just not talk about this sh*t on the news because they're afraid people will run mob-like through the streets, looting and pillaging?!

Predicting the future with Quantum Physics?
A single splitter sends 1/2 of all the photons 5 LY away. While a detector will observe if an interfereance pattern is seen within a few seconds.
If you see an interferance pattern... it tells you that the detector 5 LYs away did not see the photons.
If you see an normal grouping pattern... it tells you that the detecter will see the photons.
Using this experiment, it will tell you if something in the future is in a position to block the stream of photons? Wow.

So how the f*ck is that possible. I see the info, I see the results but WTF!!! God i love quantum physics. so the particle acts like a particle when we can detect its path, but a wave when theres no way for us to know, so by us observing the photon we make it matter but if we have no way of knowing what path it took its a wave pattern. how is that possible. Just by us knowing what way the photon travels and seeing it do so makes it matter, like we see it so therefor it exists, but if we dont observe

4 because (a) its the rating it has now, and (b) half the time it sounds as if youre trying to lead the viewer to believe a non-truth, partially because of fast explanations. now i do believe all this, and now plan to take a few ...quantum physics classes later on......but i cant help but feel mislead.

could it be that the interference pattern on the detector actually determines which detector is hit 5 light years away, and not the other way around? Also is it not true that in the photon's frame of reference no time has passed between the events of original detector bing hit and the detectors 5 light years away. In the photon's frame of reference its simultaneous? That would make a lot of sense then, if you think about special theory of relativity.

what am trying to wrap my head around.. isnt it the case that all of these events, the hitting of all detectors splitters mirrors , is all determined simultaneously in the photon's frame of reference? I seem to recall that in the lightspeed moving frame of reference time is much diferent then in the stationary lab reference.

Have you ever touched a tit? No seriously I really want to know. Do you use your extensive and mundane knowledge of quantum physics to pick up women? Does it work at all? No one who is getting laid gives sh*t about some acne ridden teeangers obssession with science. GTFO and MORE N*GG* CAWK

I love that people here are trying to like dispute this stuff... It shouldn't be shocking or a revelation or hard to believe, because everyone on the internet should have already found the basics of quantum physics out on their own automatically just out of interest. It's basic human knowledge. If you havn't already taken the time by now to find it out then i'm surprised you can even read/type.

I have one question- If the detectors record the result, but before we check and see what esult theyrecorded, they self destructed (in other words, the result was recorded, but the recording was destroyed) would the photons land in an interference or non interference pattern?

lol... lightyear definitions notwithstanding... yeah it's pretty cool although not much beyond what I already knew cause I'm a nerd. And you got me with the music too... I was thinking about putting DI on after YTMNDing ;P

Okay already, my mind is BLOWN. But seriously dude, that was a little too long.. perhaps you ought to work on breaking it down a little simpler? I found Wikipedia's article on this experiment much easier to understand than your four-part YTMNDs. (And I have a general understanding of particle physics - I

[Repost because my original comment got hosed]
Okay already, my mind is BLOWN. But seriously dude, that was a little too long.. perhaps you ought to work on breaking it down a little simpler? I found Wikipedia's article on this experiment much easier to understand than your four-part YTMNDs. (And I have a general understanding of particle physics - I *heart* Brian Greene) Still, I give you three stars for effort and for a good choice of music.

what really bothers me is when people who have obviously done quantum physics, etc. in university complain about these ytmnd's being too simplistic. yes, because we are all born with a basic knowledge of quantum physics, excuse us for being your mental inferiors. even if it IS relatively simple, just because someone hasn't learned something that they don't need to know doesn't make them stupid.

^^ Well don't blame me because you want to make your own definition for YTMND. Let's see what the creator has to say......Ok, so what's YTMND?
YTMND is a site created for the purpose of furthering the creativity of its users. It stems from an idea that, using sound, and image, and some text, the users can convey a point, funny, political, or otherwise, to the general media.

Sorry if I insulted you(as it appears), but you are the one who is trying to convince US. There are more than 30 comments on your previous ytmnd's from people who feel the same way. Please, derive SOMETHING from SOME empirical formula. Show a shread of integrity instead of just being offended of someone questioning you. It is the very nature of science.

What are you talking about tool? You think that the detectors make the photons act like matter? Even though the delayed choice experiment in pt4 shows that without changing one single measurement on the signal particle, we can affect the result of it by measuring it's idler photon. What is there left to explain?

Hey, here's the thing about convincing people with average cognitive ability: they aren't scared of people who tell them things they don't understand. Here's the thing about people who have the education equivalent to a goldfish: they want more n*gga cawk.

Okay, you're misleading these people. The detection of the photon means that something must be fired at it, ultimately collapsing the wave function by touching it and throwing it off course. The uncertainly principal says that you cannot know the exact position and velocity of an electron, photon etc. Either you know 100% where it is and 0% velocity and so on. The photon does not "know" it's being observed. Wikipedia "Uncertainty Principal".

Misleading? Watch pt 4 again. I don't know how I can make it any more clear. They affect the outcome of the SIGNAL photon without every doing anything additional to it. Simply by detecting the idler photon (and only if it relays which path info) they can affect whether the signal photons will produce an interference pattern or not.

What milky is TRYING to say is "Any sort of thinking beyond "What McDonald combo do I want today?" requires too much effort as it is. That's all. Milky isn't trying to insult you, just try to explain to the public at his/her preference to think less, and be controlled by our instincts more. It's not wrong, it's just different.

Simple similar example -not the same- If I had a camera in two hallways, that met one point (like a V, with one hallway to the left, and one to the right) and I (not looking), threw a ball down into the hallways, it could go in the left or right hallway. If I don't look at the camera footage, it would have gone in both hallways (setting it in stone. Once the information is know, it's not something you can change). If I watch where the ball goes, it will go in A OR B, and never have the option to go in both.

Ummm I think I refering to the first YTMND that talked about lasers. Not player h8ing or anything, I love you if anything since people who have a decent understanding in these kinds of sciences are rare.

In conclusion to all that has been said so far I think it is obvious that, as I said before, we know very little about this strange phenomenon(sp?). Much is to be learned, just as much was to be learned 1000 years ago.

hmm, Is there a way to switch between the interference pattern and the deterministic pattern? Could you say, have a switch that when you hit one way, a deterministic pattern would show up and hit another way, an interference pattern would show up?
because if you could, you'd just have invented an inter-galactic telegraph
*mind blown*
although I'm still not 100% you aren't getting your facts messed up

Well, an intergalactic telegraph wouldn't work with this experiment. Remember, the possibility of knowing which path will render a noninterference pattern. So simply switching it off for a second, doesn't completely destroy the possibility of ever knowing which path.
Now there are theories of an "intergalactic telegraph" as you say with manipulating the spin of entangled particles. Maybe 5 will be on that. Not really alot of good graphics and experiments that I know of that I can throw out in 5 mins.

Awesome, but seriously, why is this concept so hard to grasp? I mean it's no more complicated than the Heisenberg Uncertainty Principle, which is "The more precisely the position is determined, the less precisely the momentum is known in that instant, and vice versa." Maybe you could make one on that.

I recall a little of quantum physics... could this cause a causality violation? I.e. the guys five light years away decide to randomly smash all the detectors halfway after the photons start arriving, and back on earth suddenly you get nothing but wave pattern. Doesn't that imply that information that the detectors will have stopped in five years travelled faster than light (and therefore back in time) to you?

I submit to the "crazy" aspect of this, but ever since the flashlight on the wall, all of these are just increasingly complicated ways of coming up with the same answer. I know no one will read this because this comment page is huge...

I got bored after a while, [too many words, repeating of same words, repeating simple concepts over and over, etc] and couldnt make it through. Maybe make the next one with the mind-blowing part first, then explain how it happened.